Information storage medium

ABSTRACT

An information storage medium having a plurality of information storage layers, each of which includes an optimal power control (OPC) area for obtaining an optimal recording condition. Optimal power control areas in odd-numbered and even-numbered information storage layers viewed from a direction in which light is incident upon the information storage medium are disposed one on another to not directly face each other. An actually usable area of an optimal power control area in each of the information storage layers varies depending on use circumstances of each of the information storage layers. Therefore, when an OPC area of one information storage layer performs OPC, this OPC does not affect another information storage layer. Also, an area of each of the information storage layers can be efficiently used.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of Korean Patent ApplicationNo. 2003-43573, filed on Jun. 30, 2003 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to recordable information storagemedia, and more particularly, to an information storage medium having aplurality of information storage layers, by which an area of theinformation storage layers can be efficiently used while minimizing aninfluence of an optimal power control (OPC) process executed in an OPCarea, included in each of information storage layers, upon otherinformation storage layers.

[0004] 2. Description of the Related Art

[0005] General information storage media are widely used as informationrecording media of optical pickup apparatuses for recording/reproducingdata in a non-contact way. Optical disks are used as the informationstorage medium and classified as compact disks (CDs) or digitalversatile disks (DVDs) according to their information storage capacity.Examples of recordable, erasable, and reproducible optical disks are 650MB CD-R, CD-RW, 4.7 GB DVD+RW, and the like. Furthermore, highdefinition-DVD (HD-DVD) having a recording capacity of 25 GB or greaterare under development.

[0006] As described above, information storage media have been developedto have a greater recording capacity. The recording capacity of aninformation storage medium can be increased in two representative waysof: 1) reducing the wavelength of a recording beam emitted from a lightsource; and 2) increasing the numerical aperture of an objective lens.In addition, there is a way of forming a plurality of informationstorage layers.

[0007]FIGS. 1A and 1B schematically illustrate a dual-layeredinformation storage medium having first and second information storagelayers L0 and L1. The first and second information storage layers L0 andL1 include first and second optimal power control (OPC) areas 111 and121, respectively, for obtaining optimal writing power and first andsecond defect management area (DMAs) 115 and 125, respectively. Thefirst and second OPC areas 111 and 121 face each other (i.e., the OPCareas are at a common radius relative to an inner or outer boundary ofthe information storage medium).

[0008] Data is recorded in the first and second OPC areas 111 and 121using various levels of writing power to find the optimum writing power.Hence, data may be recorded with a higher level of power than theoptimum writing power. Table 1 shows variations in the jittercharacteristics of each of the first and second information storagelayers L0 and L1 when data is recorded in the OPC areas 111 and 121 withdifferent levels of writing power. TABLE 1 Writing power about 20%higher than normal writing Normal writing power power L0 WrittenUnwritten Writing Written Writing Written L1 Unwritten Writing WrittenWriting Written Writing Jitter L0 5.9% 6.0% 5.8% 5.9% → 6.4% L1 6.3%6.2% 6.3% 6.2% → 6.3% Writing L0 6.4 6.3 6.3 7.5 6.4 Power L1 6.0 6.06.2 6.0 7.2

[0009] According to Table 1, if data is recorded with normal writingpower, the jitter characteristics of the first or second informationstorage layer L0 or L1 keep constant. On the other hand, if data isrecorded with writing power about 20% higher than the normal writingpower, the jitter characteristics of the OPC area of the first or secondinformation storage layer L0 or L1 in which data has already beenrecorded are degraded. If data is recorded on one of the first andsecond information storage layers L0 and L1 with writing power more than20% higher than the normal writing power, it can be expected that thejitter characteristics of the other information storage layer may befurther degraded.

[0010] Hence, if the first and second OPC areas 111 and 121 of the firstand second information storage layers L0 and L1 exist within an equalradius as shown in FIGS. 1A and 1B, one of them may not be usable.

[0011] The recording status of one of the first and second OPC areas 111and 121 may affect the recording characteristics of the other OPC area.For example, as shown in FIG. 1B, if data has been recorded on a part111 a of the first OPC area 111 and no data has been recorded on theresidual area 11 b thereof, the recording property of a part of thesecond OPC area 121 which corresponds to the occupied part 111 a of thefirst OPC area 111 is different from that of a part of the second OPCarea 121 which corresponds to-the unoccupied part 111 b of the first OPCarea 111. In other words, since the transmittance of a laser withrespect to the occupied part 111 a of the first OPC area 111 isdifferent from the transmittance of a laser with respect to theunoccupied part 111 b thereof, the recording property of the second OPCarea 121 may be irregular over the area.

[0012] As described above, if the first and second OPC areas aredisposed within an equal radius, they may not properly function.

SUMMARY OF THE INVENTION

[0013] According to an aspect of the present invention, there isprovided an information storage medium having a plurality of informationstorage layers, by which an area of the information storage layers canbe efficiently used while minimizing an influence of optimal powercontrol (OPC) executed in an OPC area included in each of informationstorage layers upon other information storage layers.

[0014] According to an aspect of the present invention, there isprovided an information storage medium having a plurality of informationstorage layers, each of which includes an optimal power control area forobtaining an optimal recording condition, wherein the optimal powercontrol areas in odd-numbered and even-numbered information storagelayers are disposed within different radiuses of the information storagemedium and the size of an actually usable area of an optimal powercontrol area in each of the information storage layers varies dependingon use circumstances of each of the information storage layers.

[0015] According to another aspect of the present invention, there isprovided an information storage medium having a plurality of informationstorage layers, each of which includes an optimal power control area forobtaining an optimal recording condition, wherein the optimal powercontrol areas in odd-numbered and even-numbered information storagelayers are disposed within different radiuses of the information storagemedium and one of the odd-numbered and even-numbered information storagelayers includes a usable area for a predetermined purpose that faces theoptimal power control area of the other information storage layer.

[0016] Additional aspects and/or advantages of the invention will be setforth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and/or other aspects and advantages of the presentinvention will become more apparent by describing in detail exemplaryembodiments thereof with reference to the attached drawings of which:

[0018]FIGS. 1A and 1B are views illustrating an influence of an optimalpower control (OPC) area upon an area other than the OPC area in aconventional dual-layered information storage medium;

[0019]FIG. 2 illustrates a layout of a data area of a dual-layeredinformation storage medium according to an embodiment of the presentinvention;

[0020]FIGS. 3A and 3B illustrate a layout of a data area of adual-layered information storage medium according to another embodimentof the present invention;

[0021]FIGS. 4A and 4B illustrate a layout of a data area of adual-layered information storage medium according to another embodimentof the present invention;

[0022]FIGS. 5A through 5D illustrate a layout of a data area of adual-layered information storage medium according to another embodimentof the present invention;

[0023]FIG. 6 illustrates a layout of a data area of a dual-layeredinformation storage medium according to an embodiment of the presentinvention;

[0024]FIG. 7 illustrates a layout of a data area of a dual-layeredinformation storage medium according to another embodiment of thepresent invention; and

[0025]FIG. 8 is a block diagram of a recording and/or reproducingapparatus according to an embodiment of the present invention; and

[0026]FIG. 9 is a more detailed block diagram of the optical recordingand/or reproducing apparatus of FIG. 8.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Reference will now be made in detail to the embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below to explain the presentinvention by referring to the figures.

[0028] Referring to FIG. 2, an information storage medium according toan embodiment of the present invention includes at least two informationstorage layers L0 and L1. Each of the information storage layers L0, L1includes an optimal power control (OPC) area 211, 223 for obtainingoptimal power and a reserved area 213, 221. The OPC areas 211, 223 ofthe information storage layers L0, L1 are disposed within differentradii such as not to face each other. Although not shown, each of theinformation storage layers may include a map area adjacent to the OPCarea 211, 223.

[0029] The information storage medium shown in FIG. 2 includes first andsecond information storage layers L0 and L1. The first informationstorage layer L0 includes a first OPC area 211, a first reserved area213, and a first disk information (DI) area 215. The second informationstorage layer L1 includes a second reserved area 221, a second OPC area223, and a second DI area 225. The first and second DI areas 215 and 225store data that is updated upon every data recording, such as, anaddress of a used part of an OPC area, information about a status of aninformation storage layer, and the like. Examples of the informationabout a status of an information storage layer include a recording mode,and an address recorded last according to a recording mode.

[0030] The first and second OPC areas 211 and 223 in the informationstorage layers L0 and L1 are disposed within different radii of theinformation storage medium such that the first and second OPC areas 211and 223 do not face each other. More specifically, the second reservedarea 221 is disposed in an area of the second information storage layerL1 opposite to the first OPC area 211 of the first information storagelayer L0, and the first reserved area 213 is disposed in an area of thefirst information storage layer L0 opposite to the second OPC area 223of the second information storage layer L1.

[0031] The first and second DI areas 215 and 225 of the first and secondinformation storage layers L0 and L1, respectively, are disposed withinan identical radius of the information storage medium. Defect managementareas (DMAs) may be used instead of or in addition to the DI areas 215and 225.

[0032]FIGS. 3A and 3B illustrate an information storage medium accordingto another embodiment of the present invention, in which the firstinformation storage layer L0 includes a first OPC area 311, a firstreserved area 313, and a first disk management area (DMA) 315, and thesecond information storage layer L1 includes a second reserved area 321,a second OPC area 323, and a second DMA 325.

[0033] Referring to FIGS. 3A and 3B, directions of data recording ineach OPC area 311, 323 and a reserved area 313, 321 of each informationstorage layer L0, L1, (i.e., directions of the use of the OPC area 311,323 and the reserved area 313, 321) are identical. In other words, whiledata is recorded in an OPC area 311, 323 and a reserved area 313, 321 ofeach information storage layer L0, L1 in an identical direction, data isrecorded in facing areas of different information storage layers L0, L1in opposite directions. That is, the facing areas of differentinformation storage layers L0, L1 are used in opposite directions sothat they are not used together upon data recording.

[0034] In FIG. 3A, regardless of a track spiral direction of theinformation storage medium, data is recorded in the first OPC area 311and the first reserved area 313 of the first information storage layerL0 in an identical direction from an inner boundary to an outer boundaryof the information storage medium. In other words, the first OPC area311 and the first reserved area 313 are used in the identical directionfrom the inner boundary to the outer boundary of the information storagemedium. Data is recorded in the second reserved area 321 and the secondOPC area 323 of the second information storage layer L1 in an identicaldirection from the outer boundary to the inner boundary of theinformation storage medium. In other words, the second reserved area 321and the second OPC area 323 are used in the identical direction from theouter boundary to the inner boundary of the information storage medium.Thus, the facing OPC and reserved areas of the first and second storagelayers L0 and L1 are used in opposite directions.

[0035] In FIG. 3B, regardless of the track spiral direction of theinformation storage medium, data is recorded in the first OPC area 311and the first reserved area 313 of the first information storage layerL0 in the identical direction from the outer boundary to the innerboundary of the information storage medium. In other words, the firstOPC area 311 and the first reserved area 313 are used in the identicaldirection from the outer boundary to the inner boundary of theinformation storage medium. Data is recorded in the second reserved area321 and the second OPC area 323 of the second information storage layerL1 in the identical direction from the inner boundary to the outerboundary of the information storage medium. In other words, the secondreserved area 321 and the second OPC area 323 are used in the identicaldirection from the inner boundary to the outer boundary of theinformation storage medium, but opposite the direction of use of thefirst OPC area 311 and the first reserved area 313.

[0036]FIGS. 4A and 4B illustrate an information storage medium accordingto another embodiment of the present invention, in which the firstinformation storage layer L0 includes a first OPC area 411, a firstreserved area 413, and a first DMA 415, and the second informationstorage layer L1 includes a second reserved area 421, a second OPC area423, and a second DMA 425.

[0037] Referring to FIGS. 4A and 4B, directions of data recording in anOPC area 411, 423 and a reserved area 413, 421 of each informationstorage layerL0, L1 (i.e., directions of the use of the OPC area 411,423 and the reserved area 413, 421) are opposite. In other words, whiledata is recorded in an OPC area 411, 423 and a reserved area 413, 421 ofeach information storage layer L0, L1 in opposite directions, data isrecorded in facing areas of different information storage layers inopposite directions. That is, the facing areas of different informationstorage layers are used in opposite directions so that they are not usedtogether upon data recording.

[0038] In FIG. 4A, regardless of the track spiral direction of theinformation storage medium of FIG. 2, directions of data recording in afirst OPC area 411 and a first reserved area 413 of a first informationstorage layer L0 are opposite. That is, directions of the use of thefirst OPC area 411 and the first reserved area 413 are from an innerboundary to an outer boundary of the information storage medium and fromthe outer boundary to the inner boundary, respectively. Directions ofdata recording in a second reserved area 421 and a second OPC area 423of a second information storage layer L1, that is, directions of the useof the second reserved area 421 and the second OPC area 423, are fromthe outer boundary to the inner boundary of the information storagemedium and from the inner boundary to the outer boundary, respectively.

[0039] In FIG. 4B, regardless of the track spiral direction of theinformation storage medium, directions of data recording in the firstOPC area 411 and the first reserved area 413 of the first informationstorage layer L0, (i.e., directions of the use of the first OPC area 411and the first reserved area 413) are from the outer boundary to theinner boundary of the information storage medium and from the innerboundary to the outer boundary, respectively. Directions of datarecording in the second reserved area 421 and the second OPC area 423 ofthe second information storage layer L1, (i.e., directions of the use ofthe second reserved area 421 and the second OPC area 423) are from theinner boundary to the outer boundary of the information storage mediumand from the outer boundary to the inner boundary, respectively.

[0040] In FIGS. 3A and 3B or FIGS. 4A and 4B, it is understood that theorder of the OPC area and the reserved area arranged in each of thefirst and second information storage layers L0 and L1 may be invertedaccording to different aspects.

[0041] In the information storage media of FIGS. 3A and 3B and FIGS. 4Aand 4B, addresses of used parts of the first OPC areas 311 and 411 andthe second OPC areas 323 and 423 are recorded in the first reservedareas 313 and 413 and the second reserved areas 321 and 421,respectively. Hence, the size of an actually usable area of an OPC areaof an information storage layer varies by a used area of a reserved areaof an adjacent information storage layer depending on the environmentsof the use of each information storage layer, for example, depending ona type of data recorded in each information storage layer or a frequencyof the use of each information storage layer.

[0042]FIGS. 5A through 5D illustrate an information storage mediumaccording to another embodiment of the present invention, which includesmap areas 512, 522 for storing addresses of used parts of the OPC areas511, 523 in information storage layers L0 and L1 are disposed adjacentto the OPC areas 511, 523. In contrast with FIGS. 3A and 3B and FIGS. 4Aand 4B, a reserved area allocated in each of the information storagelayers L0 and L1 is used for a purpose other than the storage of theaddresses of used parts of the OPC areas 511, 523. When such a map areais disposed adjacent to an OPC area 511, 523 in each information storagelayer as described above, a usable part of the OPC area 511, 523 can berapidly identified before the OPC is performed in each informationstorage layer L0, L1. Thus, a time required to perform the OPC can beshortened.

[0043] The addresses of the OPC areas 511, 523 may be recorded in themap area in various forms, for example, in the form of a bitmap. The maparea 512, 522 may be replaced by a disk information (DI) area which canstore not only OPC information but also information updated upon everydata recording, for example, an address finally recorded in a user areaor the like.

[0044] In FIGS. 5A through 5D, the first information storage layer L0includes a first OPC area 511, a first map area 512, a first reservedarea 513, and a first DMA 515, and the second information storage layerL1 includes a second reserved area 521, a second map area 522, a secondOPC area 523, and a second DMA 525. The first and second map areas 512and 522 are disposed within an identical radius of the informationstorage medium, and the first and second DMAs 515 and 525 are similarlysituated on a different radius of the information storage medium.

[0045] Generally, the information storage media illustrated in FIGS. 5Aand 5B are formed by further allocating the first and second map areas512 and 522 in the information storage media of FIGS. 3A and 3B. Theinformation storage media illustrated in FIGS. 5C and 5D are formed byfurther allocating the first and second map areas 512 and 522 in theinformation storage media of FIGS. 4A and 4B. As described above, thereserved areas 513, 521 illustrated in FIGS. 5A through 5D are not usedto store data updated upon every data recording, such as, the addressesof used parts of the OPC areas 511, 523.

[0046]FIG. 6 illustrates an information storage medium according toanother embodiment of the present invention. Considering the fact thatcharacteristics of data recording in inner and outer boundaries of aninformation storage medium may be different, OPC areas 611, 631, 617,637 are disposed in at least one of a lead-in area 610 and a lead-outarea 630 which are disposed on opposite sides of a data area 620,respectively. In the first and second information storage layers L0 andL1, first and second OPC areas 611 and 617 of the lead-in area 610 andfirst and second OPC areas 631 and 637 of the lead-out area 630 may bedisposed on both sides of third and fourth data areas 621 and 623 thedata area 620 using one of the arrangements illustrated in FIGS. 2through 5.

[0047]FIG. 7 illustrates an information storage medium according toanother embodiment of the present invention. Considering the fact thatdegrees of influence of the OPCs executed in the first and secondinformation storage layers L0 and L1 upon jitter characteristics of thefirst and second information storage layers L0 and L1, respectively, aredifferent, a reserved area 713 is allocated in one of the first andsecond information storage layers L0 and L1, and a usable area 721 isallocated in the other information storage layer.

[0048] Referring to Table 1, the OPC in the second information storagelayer L1 affects jitter characteristics more than the OPC in the firstinformation storage layer L0. Of course, if the thickness of a spacelayer interposed between the first and second information storage layersL0 and L1 is changed or a structure of each information storage layer ischanged, a phenomenon opposite to the above influencing phenomenon mayoccur. That is, the OPC in the first information storage layer L0affects jitter characteristics more than the OPC in the secondinformation storage layer L1. In the information storage medium of FIG.7, the OPC in the second information storage layer L1 affects jittercharacteristics more than the OPC in the first information storage layerL0.

[0049] In the information storage medium of FIG. 7, the firstinformation storage layer L0 includes a first OPC area 711, a firstreserved area 713, and a first DI area 715, and the second informationstorage layer L1 includes a usable area 721, a second OPC area 723, anda second DI area 725. The usable area 721 of the second informationstorage layer L1 faces the first OPC area 711 of the first informationstorage layer L0, which affects jitter characteristics less than thesecond OPC area 723 of the second information storage layer L1, and canbe used to store data used for a special purpose, such as a purpose setby a user or a manufacturer. The first and second DI areas 715 and 725are disposed within an identical radius of the information storagemedium and store OPC information or information updated upon every datarecording, such as, an address finally recorded in a user area or thelike. The DI areas 715 and 725 may be replaced by map areas that aredisposed within an identical radius of the information storage mediumand that store information about the first and second OPC areas 711 and723.

[0050] Areas arranged as illustrated in FIG. 7 can be disposed in both alead-in area and a lead-out area or in one of a lead-in area and alead-out area.

[0051]FIG. 8 is a block diagram of an optical recording and/orreproducing apparatus according to an embodiment of the presentinvention in which the information storage media of FIGS. 2-7 areimplemented. Referring to FIG. 8, the recording and/or reproducingapparatus includes a writing/reading unit 1000 and a control unit 1002.The writing/reading unit 1000 reads from and writes to the informationstorage medium 130 according to commands from the control unit 1002.Here, the information storage medium 130 includes several embodimentsshown in FIGS. 2 through 7 and the control unit 1002 controls datawriting/reading operations of the writing/reading unit 1000 so as tominimize interference between a first optimal power control area in afirst information storage layer and a second optimal power control areain a second information storage layer of the information storage medium130.

[0052] Referring to FIG. 8, according to the control of the control unit1002, the writing/reading unit 1000 records data on a disc 130, which isan information storage medium according to embodiments of the presentinvention, and reads out data in order to reproduce recorded data. Thecontrol unit 1002 controls the writing/reading unit 1000 so that thewriting/reading unit 1000 records data in predetermined recording unitblocks, or processes data read by the writing/reading unit 1000 andobtains valid data. Reproducing refers to obtaining valid data byperforming error correction for the read data, and is performed inpredetermined units. The units for performing reproduction are referredto as reproducing unit blocks. A reproducing unit block corresponds toat least one recording unit block.

[0053]FIG. 9 is a more detailed block diagram of the optical recordingand/or reproducing apparatus of FIG. 8. Referring to FIG. 9, theinformation storage medium 130 is loaded in the writing/reading unit1000. The recording and/or reproducing apparatus further includes anoptical pickup 1100 that reads from and writes to the informationstorage medium 130. The control unit 1002 includes a PC I/F 1101, a DSP1102, an RF AMP 1103, a servo 1104, and a system controller 1105, all ofwhich constitute the control unit 1002 of FIG. 8.

[0054] In the data recording operation, the PC I/F 1101 receives arecording command with data to be recorded from a host. The DSP 1102adds additional data such as a parity for error correction of the datareceived from the PC I/F 1101 and performs error correction and checking(ECC) encoding to generate an ECC block, which is an error correctionblock, and modulates the ECC block according to a predetermined method.The RF AMP 1103 converts the data output from the DSP 1102 into an RFsignal. The pickup 1100 records the RF signal output from the RF AMP1103 on the disc 130. The servo 1104 receives a command required forservo control from the system controller 1105 and servo-controls thepickup 1100.

[0055] In the data reproducing operation, the PC I/F 1101 receives areproduction command from a host (not shown). The system controller 1105performs the initialization required for reproduction. The pickup 1100emits a laser beam onto the disc 130, obtains an optical signal byreceiving a reflected beam from the disc 130, and outputs the opticalsignal. The RF AMP 1103 converts the optical signal output from thepickup 1100 into an RF signal and provides modulated data obtained fromthe RF signal to the DSP 1102 while providing a servo signal for controlof the pickup 1100 obtained from the RF signal to the servo 1104. TheDSP 1102 demodulates the modulated data, performs error correction andoutputs the resulting data.

[0056] Meanwhile, the servo 1104 performs servo control of the pickup1100, by using the servo signal received from the RF AMP 1103 and acommand required for servo control received from the system controller1105. The PC I/F 1101 transfers the data received from the DSP 1102 tothe host.

[0057] The aforementioned OPC area arrangement embodiments areapplicable to all information storage media regardless of whether atrack of each information storage layer is spiraled from an innerboundary to an outer boundary or from the outer boundary to the innerboundary. The aforementioned OPC area arrangements are also applicableto all information storage media having a plurality of informationstorage layers regardless of whether an information storage layer to bereproduced first is either an information storage layer farthest from orclosest to an optical pickup. For example, the aspects of the presentinvention described above are applicable to CD-R, CD-RW, DVD+RW, HD-DVD,Bluray, and Advanced Optical Disc (AOD) type information storage media.Although the OPC area arrangements have been described with regard to adual-layered information storage medium having two information storagelayers, they may be applied to information storage media having at leastthree information storage layers which are stacked one on another.

[0058] As described above, in an aspect of an information storage mediumhaving a plurality of information storage layers, an OPC area of oneinformation storage layer may be located to not directly face the OPCarea of another information storage layer. Information about an OPC area(that is, OPC information) in one information storage layer is recordedin a reserved area of an adjacent information storage layer that facesthe OPC area, and the directions of data recording in an OPC area of oneinformation storage layer and a reserved area of another informationstorage layer that faces the OPC area are set to be opposite. That is,directions of the use of the OPC area and the reserved area are set tobe opposite. Therefore, an influence of the OPC executed in an OPC areaof one information storage layer upon another information storage layeris minimized, and the size of an actually usable area of the OPC area ofeach information storage layer varies depending on the use circumstancesof the OPC area.

[0059] Alternatively, the OPC area of one information storage layer maybe located to not directly face the OPC area of another informationstorage layer each other, and a map area for storing OPC information isincluded between the OPC area and a reserved area of each informationstorage layer according to an aspect of the invention. Therefore, whenthe OPC area of one information storage layer performs the OPC, this OPCdoes not affect another information storage layer. Also, an area of eachinformation storage layer can be efficiently used, and a time requiredto perform the OPC can be shortened.

[0060] Alternatively, the OPC area of one information storage layer maybe located with respect to an OPC area of another information storagelayer such that the OPC areas do not face each other, and, consideringthe fact that degrees of influence of the OPC areas of two adjacentinformation storage layers upon jitter characteristics are different, areserved area is allocated in only one of the two information storagelayers, and a usable area is allocated in the other information storagelayer according to an aspect of the invention. Therefore, when the OPCarea of one information storage layer performs the OPC, this OPC doesnot affect another information storage layer, and an area of eachinformation storage layer can be efficiently used.

[0061] Although a few embodiments of the present invention have beenshown and described, it would be appreciated by those skilled in the artthat changes may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

What is claimed is:
 1. An information storage medium, comprising: aplurality of information storage layers, each of which includes anoptimal power control area for obtaining an optimal recording condition,wherein the optimal power control areas in odd-numbered andeven-numbered information storage layers are disposed within differentradiuses of the information storage medium and a size of an actuallyusable area of an optimal power control area in each of the informationstorage layers varies depending on use circumstances of each of theinformation storage layers.
 2. The information storage medium of claim1, further comprising: a reserved area in each of the informationstorage layers, wherein each of the reserved areas face the optimalpower control area of an adjacent information storage layer.
 3. Theinformation storage medium of claim 2, further comprising: a map areastoring updated information about each of the information storagelayers; and the map areas are disposed within an identical radius of theinformation storage medium.
 4. The information storage medium of claim2, wherein updated information about each of the information storagelayers is recorded in the reserved area.
 5. The information storagemedium of claim 2, wherein updated information about each of theinformation storage layers is recorded in a part of a lead-in area thatstores disk-related information.
 6. The information storage medium ofclaim 2, wherein a direction in which data is recorded in the optimalpower control area and the reserved area of the odd-numbered informationstorage layer is opposite to a direction in which data is recorded inthe optimal power control area and the reserved area of theeven-numbered information storage layer.
 7. The information storagemedium of claim 6, wherein directions in which data is recorded in theoptimal power control area and the reserved area of one informationstorage layer are identical.
 8. The information storage medium of claim6, wherein directions in which data is recorded in the optimal powercontrol area and the reserved area of one information storage layer areopposite.
 9. The information storage medium of claim 6, wherein theoptimal power control areas are formed in at least one of a lead-in areaand a lead-out area.
 10. The information storage medium of claim 3,wherein a first direction in which data is recorded in the optimal powercontrol area, the map area and the reserved area of the odd-numberedinformation storage layer is opposite to a second direction in whichdata is recorded in the optimal power control area, the map area and thereserved area of the even-numbered information storage layer.
 11. Theinformation storage medium of claim 10, wherein directions in which datais recorded in an optimal power control area and a reserved area of oneinformation storage layer are opposite.
 12. An information storagemedium, comprising: a plurality of information storage layers, each ofwhich includes an optimal power control area for obtaining an optimalrecording condition, wherein the optimal power control areas inodd-numbered and even-numbered information storage layers are disposedwithin different radiuses of the information storage medium and one ofthe odd-numbered and even-numbered information storage layers includes ausable area for a predetermined purpose that faces the optimal powercontrol area of the other information storage layer.
 13. The informationstorage medium of claim 12, wherein the other information storage layerfurther comprises a reserved area which faces an optimal power controlarea of the one information storage layer.
 14. The information storagemedium of claim 13, wherein: each of the information storage layersfurther comprises a map area storing updated information about each ofthe information storage layers; and the map areas are disposed within anidentical radius of the information storage medium.
 15. The informationstorage medium of claim 13, further comprising updated information abouteach of the information storage layers which is recorded in a part of alead-in area that stores disk-related information.
 16. The informationstorage medium of claim 13, wherein a direction in which data isrecorded in the optimal power control area of one of the informationstorage layers is opposite to a direction in which data is recorded inthe reserved area of the other information storage layer.
 17. Theinformation storage medium of claim 16, wherein the optimal powercontrol areas are formed in at least one of a lead-in area and alead-out area.
 18. A multilayer information storage medium, comprising:a first information storage layer comprising a first optimal powercontrol area and a first reserved area adjacent to the first optimalpower control area; and a second information storage layer adjacent tothe first information storage layer, the second information storagelayer comprising a second optimal power control area and a secondreserved area adjacent to the second optimal power control area, whereinthe first optimal power control area is aligned with the second reservedarea and the second optimal power control area is aligned with the firstreserved area.
 19. The information storage medium of claim 18, whereinthe first optimal power control area and the second optimal powercontrol area are recorded in a first direction and the first reservedarea and the second reserved area are recorded in a second directionopposite the first direction.
 20. The information storage medium ofclaim 18, wherein the first optimal power control area and the secondoptimal power control area are recorded in opposite directions withrespect to each other and the first reserved area and the secondreserved area are recorded in opposite directions with respect to eachother.
 21. The information storage medium of claim 18, furthercomprising: a first map area which stores addresses of sectors of thefirst optimal power control area in which data is recorded, the firstmap area disposed between the first optimal power control area and thefirst reserved area in the first information storage layer; and a secondmap area which stores addresses of sectors of the second optimal powercontrol area in which data is recorded, the second map area disposedbetween the second optimal power control area and the second reservedarea in the second information storage layer.
 22. The informationstorage medium of claim 21, wherein the addresses of the first andsecond optimal power control areas are recorded in the first and secondmap areas, respectively, in the form of a bitmap.
 23. The informationstorage medium of claim 21, wherein a time required to write to and readfrom the first and second optimal power control areas is shortened bythe stored addresses in the first and second map areas.
 24. Theinformation storage medium of claim 21, wherein the first optimal powercontrol area, the second optimal power control area and the first maparea are written to in a first direction and the first reserved area,the second reserved area, and the second map area are written to in asecond direction opposite the first direction.
 25. The informationstorage medium of claim 21, wherein the addresses are recorded in thefirst map area and the second map area in opposite directions withrespect to each other.
 26. The information storage medium of claim 21,wherein the first optimal power control area, the first map area, andthe first reserved area are written to in a first direction, and thesecond optimal power control area, the second map area, and the secondreserved area are written to in a second direction opposite the firstdirection.
 27. The information storage medium of claim 21, furthercomprising: a third optimal power control area in the first informationstorage layer, a third reserved area adjacent to the third optimal powercontrol area, and a third map area between the third optimal powercontrol area and the third reserved area; and a fourth optimal powercontrol area, a fourth reserved area adjacent to the fourth optimalpower control area, and a fourth map area between the fourth optimalpower control area and the fourth reserved area, wherein the thirdoptimal power control area is aligned with the fourth reserved area, thefourth optimal power control area is aligned with the third reservedarea, and the third map area is aligned with the fourth map area. 28.The information storage medium of claim 27, wherein the first optimalpower control area, map area and reserved area are disposed near aninner boundary of the information storage medium and the third optimalpower control area, map area and reserved area disposed near an outerboundary of the information storage medium.
 29. The information storagemedium of claim 27, wherein the first optimal power control area, maparea and reserved area are disposed in a lead-in area of the informationstorage medium and the third optimal power control area, map area andreserved area disposed in a lead-out area of the information storagemedium.
 30. A multilayer information storage medium, comprising: a firstinformation storage layer comprising a first optimal power control areaand a first reserved area adjacent to the first optimal power controlarea; and a second information storage layer adjacent to the firstinformation storage layer, the second information storage layercomprising a second optimal power control area and a special use areaadjacent to the second optimal power control area, the special use areastoring data for a special purpose set by a manufacturer, wherein thefirst optimal power control area is aligned with the special use areaand the second optimal power control area is aligned with the firstreserved area.
 31. A method of minimizing interference between a firstoptimal power control area in a first information storage layer and asecond optimal power control area in a second information storage layerof an information storage medium, comprising: disposing the first andsecond optimal power control areas such that each is aligned with aspecial area of the other information storage layer that is recorded inan opposite direction to minimize interference.
 32. A recording and/orreproducing apparatus, comprising: an optical pickup which records dataon and/or reads the data from a surface of an information storage mediumat an optical power; and a controller which controls the optical pickupto record and/or reproduce the data on the surface of the informationstorage medium and to determine an optimum recording power at which toset the optical power during recording, wherein the information storagemedium comprises a first information storage layer comprising a firstoptimal power control area and a first restricted use area, and a secondinformation storage layer comprising a second optimal power control areaand a second restricted use area disposed such that the first optimalpower control area is aligned with the second restricted use area andthe second optimal power control area is aligned with the firstrestricted use area, and the controller determines the optimal recordingpower according to the data recorded and/or reproduced by the opticalpickup in one of the first and second optimal power control areas. 33.The apparatus of claim 32, wherein the first and second restricted useareas are reserved areas which are recordable by the controller in adirection opposite to the first and second optimal power control areas.34. The apparatus of claim 32, wherein the first restricted area is areserved area which is recordable by the controller in a directionopposite to the first and second optimal power control areas and thesecond restricted area is a usable area which is recordable in anydirection with respect to the first and second optimal power controlareas.